1. Field of the Invention
The present invention relates to a circuit for driving a photoluminescence quenching device (PQD) and a matrix display apparatus incorporating the circuit, and a plurality of PQDs. More particularly, the invention relates to a circuit for driving a matrix display panel including PQDs as pixels, which are defined by crossings of scan lines and data lines, and a matrix display apparatus incorporating the circuit.
2. Description of the Related Art
Flat panel displays using organic light-emitting diodes (OLEDs) provide high brightness and a wide viewing angle. Using the self-emissive mode, OLEDs do not require any back light and are thus very effective under conditions of low to medium ambient light. However, with high ambient light, such as direct sunlight, a disproportionately large amount of power must be supplied to OLEDs to obtain required brightness. Moreover, high current is required in order to activate the elements having a light emitting structure. For this reason, reflective and re-emissive technologies, applied to liquid crystal displays (LCDs), are very effective for LCDs in a variety of ambient light conditions. However, when using these technologies, back light is required under conditions with low ambient light, which results in an increase in the dimensions of displays and increased power consumption.
The structure of OLEDs that can be operated both in emissive and re-emissive modes is disclosed in U.S. Published Patent Application 2002 0027537A1. A PQD has a structure similar to that of an OLED and can be operated in an emissive mode without back light and a re-emissive mode.
Driver circuits activating OLEDs are known from U.S. Pat. Nos. 6,157,356, 5,952,789, and 6,518,700. All of these driver circuits have a disadvantage in that they can realize only the emissive mode of operation of an OLED. Under conditions with high ambient light, a high current is required to activate the OLED elements in the emissive mode. This high current requirement leads to an increased fabrication cost.